Process and reactor for upgrading heavy hydrocarbon oils

Abstract

A process using supercritical water to upgrade a heavy hydrocarbon feedstock into an upgraded hydrocarbon product or syncrude with highly desirable properties (low sulfur content, low metals content, lower density (higher API) lower viscosity, lower residuum content, etc.) is described. The process does not require external supply of hydrogen nor does it use externally supplied catalysts. A reactor design to carry out the process is also described,

1 . A process for upgrading hydrocarbons comprising:
 (a) mixing hydrocarbons with a fluid comprising water that has been heated to a temperature higher than its critical temperature in a mixing zone under conditions that disfavor thermal cracking and formation of coke to form a mixture;   (b) passing the mixture to a reaction zone;   (c) reacting the mixture in the reaction zone having a substantially uniform temperature distributions and being configured to reduce the settling of solids within the reaction zone said reaction occurring under supercritical water conditions in the absence of externally added hydrogen for a residence time controlled within determined limits to allow upgrading reactions to occur;   (d) withdrawing a single-phase reaction product from the reaction zone; and   (e) separating the reaction product into gas, effluent water, and upgraded hydrocarbon phases.   
     
     
         2 . A process according to  claim 1 , wherein the hydrocarbons are heavy hydrocarbons selected from the group consisting of whole heavy petroleum crude oil, tar sand bitumen, heavy hydrocarbon fractions obtained from crude petroleum oils, heavy vacuum gas oils, vacuum residuum, petroleum tar, coal tar and their mixtures. 
     
     
         3 . A process according to  claim 1 , wherein the fluid comprising water enters the mixing zone at a temperature sufficiently higher than the critical temperature of water so as to cause the resulting mixture to have a temperature higher than the supercritical temperature of water. 
     
     
         4 . A process according to  claim 1 , wherein the heavy hydrocarbons in step (a) are at a temperature of from 100° C. to 200° C. 
     
     
         5 . A process according to  claim 1 , wherein the supercritical water conditions include a temperature from 374° C. to 1000° C., a pressure from 3,205 psia to 10,000 psia an oil/water volume ratio from 1:0.1 to 1:5 and where the residence time is from 1 minute to 6 hours. 
     
     
         6 . A process according to  claim 1 , wherein the supercritical water conditions include a temperature from 374° C. to 600° C., a pressure from 3,205 psia to 7,200 psia, an oil/water volume ratio from 1:0.5 to 1:3 and where the residence time is from 8 minutes to 2 hours. 
     
     
         7 . A process according to  claim 1 , wherein the supercritical water conditions include a temperature from 374° C. to 400° C., a pressure from 3,205 psia to 4,000 psia, an oil/water volume ratio from 1:1 to 1:2 and where the residence time is from 20 to 40 minutes. 
     
     
         8 . A process according to  claim 1 , wherein the mixture in the reaction zone is reacted in the absence of any externally supplied catalyst or promoter. 
     
     
         9 . A process according to  claim 1 , further comprising the step of heating the mixture formed in step (a) to a temperature higher than the critical temperature of water before passing the mixture to the reaction zone. 
     
     
         10 . A process according to  claim 1 , wherein the uniform temperature distribution is obtained by controlling the heat transfer area in the reaction zone, by uniformly distributing the hydrocarbon feed or by quenching. 
     
     
         11 . A process for upgrading heavy hydrocarbons comprising:
 (a) mixing heavy hydrocarbons with a fluid comprising supercritical water having a temperature higher than the critical temperature of water in a mixing zone under conditions that disfavor thermal cracking and formation of coke to form a mixture having a temperature higher than the critical temperature of water;   (b) passing the mixture to a reaction zone;   (c) reacting the mixture in the reaction zone having a substantially uniform temperature distribution and being configured to reduce the settling of solids within the reaction zone said reaction occurring under supercritical water conditions in the absence of externally added hydrogen and catalyst for a residence time controlled within determined limits to allow upgrading reactions to occur;   (d) withdrawing a single-phase reaction product from the reaction zone; and   (e) separating the reaction product into gas effluent water, and upgraded hydrocarbon phases.   
     
     
         12 . A process according to  claim 11 , wherein the hydrocarbons are heavy hydrocarbons selected from the group consisting of whole heavy petroleum crude oil, tar sand bitumen, heavy hydrocarbon fractions obtained from crude petroleum oils, heavy vacuum gas oils, vacuum residuum, petroleum tar, coal tar and their mixtures. 
     
     
         13 . A process according to  claim 11 , wherein the fluid comprising water enters the mixing zone at a temperature sufficiently greater than the supercritical temperature of water so as to cause the resulting mixture to have a temperature higher than the critical temperature of water. 
     
     
         14 . A process according to  claim 11 , wherein the heavy hydrocarbons in step (a) are at a temperature of from 100° C. to 200° C. 
     
     
         15 . A process according to  claim 11 , wherein the supercritical water conditions include a temperature from 374° C. to 1000° C., a pressure from 3,205 psia to 10,000 psia an oil/water volume ratio from 1:0.1 to 1:5 and where the residence time is from 1 minute to 6 hours. 
     
     
         16 . A process according to  claim 11 , wherein the supercritical water conditions include a temperature from 374° C. to 600° C., a pressure from 3,205 psia to 7,200 psia, an oil/water volume ratio from 1:0.5 to 1:3 and where the residence time is from 8 minutes to 2 hours. 
     
     
         17 . A process according to  claim 11 , wherein the supercritical water conditions include a temperature from 374° C. to 400 20  C., a pressure from 3,205 psia to 4,000 psia, an oil/water volume ratio from 1:1 to 1:2 and where the residence time is from 20 to 40 minutes. 
     
     
         18 . A process according to  claim 11 , wherein the mixture in the reaction zone is reacted in the absence of any externally supplied catalyst or promoter. 
     
     
         19 . A process according to  claim 11 , further comprising the step of heating the mixture formed in step (a) to a temperature higher than the critical temperature of water before passing the mixture to the reaction zone. 
     
     
         20 . A process according to  claim 11 , wherein the uniform temperature distribution is obtained by controlling the heat transfer area in the reaction zone, by uniformly distributing the hydrocarbon feed or by quenching.